1. Field of the Invention
This invention relates to devices and processes for removing asphaltenes and/or metals from crude oil to increase refinery processing of heavy hydrocarbon feedstocks.
2. Discussion of Related Art
The current trend in refining includes utilization of heavier crude oil and alternative hydrocarbon sources, such as bitumen and tar sands. These heavier materials include an increased amount of asphaltenes and an increased amount of metals and/or heavy metals, which makes processing difficult due to among other things, viscosity, fouling, and catalyst deactivation issues.
In response to this need, the petroleum refining industry has developed efforts and resources to develop new ways to solve problems associated with asphaltene-containing streams and metal-containing streams. However, such efforts have only partially succeeded in providing practical methods and devices to maintain refinery capacity.
Solvent deasphalting is a commercially practiced process to separate the asphaltenes out of the heavy oils from a bottom of atmospheric and/or vacuum distillation towers. Solvent deasphalting units require high capital expenditures and have high operating costs to recycle the solvent.
Stephenson et al., U.S. Pat. No. 6,120,678 discloses desalting adjunct chemistry and teaches asphaltene dispersing treatments to reduce the rag interface. Stephenson et al. does not teach or suggest collecting asphaltenes and/or metals in a rag layer for separation from the crude oil in a desalter.
Wilson et al., U.S. Pat. No. 3,779,895 discloses high temperature steam treatment of asphaltene-containing streams to form an emulsion that is then solvent deasphalted. Wilson et al. does not teach or suggest collecting asphaltenes and/or metals in a rag layer for separation from the crude oil in a desalter.
Jorgensen, U.S. Patent Application Publication 2005/0211602 discloses superheated steam treatment of high boiling temperature material to demetalize the feed. Jorgensen does not teach or suggest collecting asphaltenes and/or metals in a rag layer for separation from the crude oil in a desalter.
Gunnerman, U.S. Patent Application Publication 2005/0205463 discloses using ultrasound of a sufficient intensity to convert heavy hydrocarbons in an emulsion to lighter components. Gunnerman does not teach or suggest collecting asphaltenes and/or metals in a rag layer for separation from the crude oil in a desalter.
Van der Toorn et al., U.S. Pat. No. 3,730,880 discloses problems of coking and catalyst issues for hyrdroconversion units when processing materials having asphaltenes and metals. Barger, U.S. Pat. No. 4,384,948 discloses similar problems with coking and catalyst poisoning in fluidized catalytic cracking units when processing materials with asphaltenes and metals.
Although the foregoing disclosures provide advances in the art, there is still a need for a method of removing asphaltenes and/or metals from crude oil, such as improved processability, reduced fouling, reduced viscosity, improved coke product quality, and/or, reduced catalyst deactivation.